Magnetic closure device

Abstract

A magnetic closure device is configured to allow for a reduction in the magnetic gap as well as for adding mechanical strength to a cover for enclosing the magnet supply and other associated parts on one of two separate elements. The magnetic closure device includes a first element and a second element which are magnetically and mechanically coupled together and may be detached. The first element A includes an annular member formed to have a thick wall and mounted around the cover. The annular member includes ornamentation at its surface. The annular member may be formed from brass or other nonmagnetic materials, including plastics.

What is claimed is: 
     
       1. A magnetic closure device comprising: a magnetically attracting first element;   a magnetically attractable second element comprising a ferromagnetic plate;   wherein said first element comprises a cylindrical magnet having a central axial bore and first and second axial ends respectively with first and second opposite polarities, a ferromagnetic plate fixed to said first end of said cylindrical magnet, a ferromagnetic rod extending from said ferromagnetic plate of said first element into said central axial bore of said cylindrical magnet, an annular cover member covering said second axial end of said cylindrical magnet, and an annular cylindrical wall fixedly mounted around said cylindrical magnet; and   wherein said annular cylindrical wall is substantially thicker than said annular cover member.   
     
     
       2. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall is formed of plastic.   
     
     
       3. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall is formed of metal.   
     
     
       4. A magnetic closure device as recited in claim 1, wherein ornamentation is provided at a periphery of said annular cylindrical wall of said first element.   
     
     
       5. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall has a gradually increasing height from a first peripheral location thereof to a second peripheral location thereof diametrically opposite said first peripheral location.   
     
     
       6. A magnetic closure device as recited in claim 1, further comprising means for guiding said second element toward said second end of said cylindrical magnet.   
     
     
       7. A magnetic closure device as recited in claim 1, wherein said annular cover member is inclined in a direction downwardly and radially inwardly into said central axial bore of said cylindrical magnet.   
     
     
       8. A magnetic closure device as recited in claim 7, wherein said annular cover member is integral with said annular cylindrical wall.   
     
     
       9. A magnetic closure device as recited in claim 1, wherein an end of said annular cylindrical wall adjacent said second end of said cylindrical magnet is inclined in a direction downwardly and radially inwardly toward said central axial bore of said cylindrical magnet.   
     
     
       10. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall includes means for mechanically retaining said second element in engagement with said first element.   
     
     
       11. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall has a reduced diameter shoulder at an end thereof adjacent said second end of said cylindrical magnet; and   said ferromagnetic plate of said second element includes an annular flange depending from a periphery thereof, said annular flange being engageable about said reduced diameter shoulder of said annular cylindrical wall.   
     
     
       12. A magnetic closure device as recited in claim 1, wherein said second end of said cylindrical magnet extends beyond said annular cylindrical wall so as to constitute a reduced diameter shoulder of said first element; and   said ferromagnetic plate of said second element includes an annular flange depending from a periphery thereof, said annular flange being engageable about said reduced diameter shoulder of said annular cylindrical wall.   
     
     
       13. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall has a recess formed at an outer periphery thereof; and   said ferromagnetic plate of said second element includes a projection depending from a periphery thereof, said projection being engageable in said recess of said annular cylindrical wall.   
     
     
       14. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall includes an inwardly directed annular flange extending over a peripheral portion of said annular cover member.   
     
     
       15. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall includes a protruding part protruding radially inwardly and upwardly above said second end of said cylindrical magnet.   
     
     
       16. A magnetic closure device as recited in claim 1, wherein said annular cylindrical wall includes a radially inwardly extending annular protrusion extending over said second end of said cylindrical magnet so as to define a circular groove between said annular protrusion and said second end of said cylindrical magnet.   
     
     
       17. A magnetic closure device as recited in claim 16, wherein said annular protrusion comprises a tapered annular protrusion.   
     
     
       18. A magnetic closure device as recited in claim 16, wherein said annular protrusion comprises a stepped annular protrusion.   
     
     
       19. A magnetic closure device as recited in claim 1, wherein said annular cover member is integral with said annular cylindrical wall.   
     
     
       20. A magnetic closure device as recited in claim 1, wherein said ferromagnetic rod of said first element extends in said central axial bore of said cylindrical magnet to approximately half the height of said cylindrical magnet.   
     
     
       21. A magnetic closure device as recited in claim 1, wherein said second element further includes a ferromagnetic rod extending from said ferromagnetic plate of said second element and being sized to be insertable into said central axial bore of said cylindrical magnet of said first element.   
     
     
       22. A magnetic closure device as recited in claim 1, further comprising a covering member including a cylindrical sidewall interposed between said cylindrical magnet and said annular cylindrical wall, a first annular end wall extending from one end of said cylindrical sidewall and radially inwardly beneath said ferromagnetic plate of said first element, and a second annular end wall extending from another end of said cylindrical sidewall and radially inwardly therefrom.   
     
     
       23. A magnetic closure device as recited in claim 22, wherein said second annular end wall of said covering member constitutes said annular cover member.   
     
     
       24. A magnetic closure device as recited in claim 1, wherein said ferromagnetic rod of said first element extends into and terminates within said central axial bore of said cylindrical magnet.   
     
     
       25. A magnetic closure device as recited in claim 1, wherein a thickness of said annular cover member constitutes an entirety of a magnetic gap between said second end of said cylindrical magnet and said ferromagnetic plate of said second element when said second element is engaged with said first element.